ps

Senior Theses: 2005-2006

Honors Thesis: The effects of supplemental stimuli within response sequences
an honors thesis by Kimberly Collins
Faculty advisor: Alliston Reid, Ph.D.
Kim Collins presented this research as a paper at the annual conference of the Association for Behavior
Analysis International in Atlanta in May, 2006
 
 

The present study examined the role of a discriminative stimulus in a four-lever sequence in rats and, in two phases, measured its effect on immediate responding and responding later in the sequence. Phase 1 presented a discriminative stimulus after the first response in alternating trials. Accuracy rates were compared between trials with and without the discriminative stimulus. Phase 2 examined the accuracy rates when the stimulus was moved to a different position in the sequence. Three subjects demonstrated no differences between any of the conditions. A blocking effect was attributed to the findings. One subject produced higher accuracies in trials with the discriminative stimulus.

Senior Theses:
Stimulus value in high-order sign tracking
Lauren Bayne, Morgan Roberts, and Becky Sasso
Faculty Advisor: Alliston Reid, Ph.D.
 

This study was a follow-up to Reid (2004) which observed that the initial stimuli were the most resistant to change in a successive stimulus array. The results obtained in that experiment were inconsistent with many of the major theories today that assume Pavlovian contingencies are solely responsible for stimulus value. The current study eliminated all operant contingencies to produce a strictly Pavlovian procedure that presented the same three key colors to pigeons in a sign-tracking task. Two resistance-to-change manipulations were implemented. In the prefeeding RTC manipulation, the terminal stimuli were most resistant to change, suggesting that operant contingencies were involved in the findings of Reid (2004), contrary to the predictions of Behavioral momentum theory. In the short intertrial interval RTC manipulation, only Pigeon 147 displayed an increase in responding which differed from the predicted effect. This increase in responding may be explained by arousal theory.

The Effects of Acute Pain on the Perception of Time in Humans
Susannah Dugan, Kate Evette, Brooke Johnson, and Amanda McMillan
Faculty Advisor: John Lefebvre, Ph.D.
 
 

To date, there has been little or no research on how pain affects the internal clock.  This study examines the effect of pain on the internal clock’s ability to time a stimulus.  Pain was expected to influence stimulus duration timing by speeding up the “internal clock” and making tones seem longer in duration than they actually were.  Participants were trained to discriminate between a short standard tone and a long standard tone.  During the experiment, participants placed their non-dominant arm in ice water or in room temperature water while listening to short, long, and intermediate tones.   For each tone, they were asked to indicate whether the tone was short or long by pressing 1 for short and 2 for long.  They were also asked to rate their pain after each trial.  Results indicated that pain had no significant effect on timing.  Further research using more subjects and shorter stimulus durations needs to be conducted in order to make a more definite conclusion.

The role of discriminative stimuli in four-lever response sequences
Meaghan Crawley, Jordan Fanney, and Leandra Parris

Faculty Advisor: Alliston Reid, Ph.D.
 
 

The present study examined the role of a discriminative stimulus in a four-lever sequence in rats and, in two phases,  measured its effect on immediate responding and responding later in the sequence. Phase 1 presented a discriminative stimulus after the first response in alternating trials. Accuracy rates were compared between trials with and without the discriminative stimulus. Phase 2 examined the accuracy rates when the stimulus was moved to a different position in the sequence. Three subjects demonstrated no differences between any of the conditions. A blocking effect was attributed to the findings. One subject produced higher accuracies in trials with the discriminative stimulus.

The effect of self-awareness on children's peer impression
Courtney Abbott, Kiri Ferguson, Peaches Lipscomb, Kelsey Rogers, and Anya Young
Faculty Advisor: Cecile McAninch, Ph.D. 
 

Children begin to make impressions on one another as early as age five. This study examined how peer impressions are formed and used self-awareness to induce increased prosocial behavior toward target children seen in a videotape. Fifty children, ages eight through twelve, were divided into four groups: self-aware - shy expectancy, self-aware - outgoing expectancy, not self-aware - shy expectancy, and not self-aware - outgoing expectancy. Each child completed several ratings scales about themselves and about a target child seen in a videotape. Results showed that no significant effects were found for self-awareness, but significant effects were found for expectancy x time. Children in the outgoing expectancy rated the target more positively on all items.
 

 A role for taste in the detection of linoleic but not oleic acid in rats
Ashley Adamson, Mallory Bramlett, Sarah Evans, Lauren Gasque, Ryn Lister
Faculty Advisor: David Pittman, Ph.D.
 

Palatability and its role in detecting fats has been mostly neglected in modern research.  This experiment uses conditioned taste aversion (CTA) to determine the role of the chorda tympani nerve in tasting oleic acid (OA) and linoleic acid (LA).  Forty-eight male Sprague-Dawley rats were divided into six experimental groups governed by having the chorda tympani nerve transected (CTX) or not (SHAM), conditioned to LA or OA, and injected with LiCl or NaCl during CTA.  On test day, all rats were presented with 44, 88, and 176 µM of OA and LA and 88 and 176 µM of lauric acid (LC) in the Davis Rig.  Results showed that rats conditioned to LA were able to detect LA and OA.  Transecting the chorda tympani nerve eliminates the detection of OA and significantly compromises the detection of LA.  All animals conditioned with OA were unable to detect any of the fatty acids.